Common defects of metal mold casting and the prevention methods

Common defects of metal mold casting and the prevention methods:
After years of research and production experience, Henan Sebon Industries Co., LTD accumulate the common defects of metal castings and prevention plan, this plan is jointly concluded by our scientific research personnel and first-line employees, hope to provide users with more convenience.

1 porosity
prevention measures of porosity occurrence: modify the unreasonable watering riser system, make the flow smooth, avoid gas involving in. The mould and cores should be preheated in advance, then coating, it must be baked thoroughly before use. Design the mold and core should be taken enough exhaust measures into account.

2 pinhole
Measures to prevent pinhole: it is forbidden to use the contaminated casting aluminum alloy material, with organic compounds, and materials that are serious oxidation corrosion . Control smelting process, enhance the gas refining. Control the metal mold coating thickness, when thick ,it is easy to generate pinhole. Mold temperature should not be too high, the casting chilling measures were adopted for thick wall parts, such as copper blocks or watering, etc. When using sand mold should strictly control water, try to use dry core.

3 oxidation slag
Oxidation slag prevention measures: strictly control the melting process, rapid melting, reduce oxidation, wipe off slag thoroughly. Al - Mg alloy must be melt under cover agent. Melting pot, tools should be clean, can not have oxide, and should be preheated, paint should be dry before use. Design of gating system must have a current regulator, buffer, skimming skills. Using tilt pouring system, the flow must be stable and does not produce secondary oxidation. Choosing the coating with strong adhesion strength, does not produce flake when pouring process into the casting in order to avoid forming slag.

4 loose
Measures to prevent casting becoming loose:set watering riser reasonably, ensure its solidification, and the feeding capacity. Lower working temperature of metal mould appropriately. Control the coating thickness,thin the thick wall . Adjust the cooling rate of metal mold parts, thick-walled castings have bigger chilling ability. Decrease the metal pouring temperature properly.

5 heat cracking
Measures to prevent cracking: actual pouring system should avoid local overheating, reduce internal stress. Mould and cores must ensure the gradient above 2 ° ,upon the watering riser coagulate ,can core-pulling molding, when necessary sand core can substitute for metal cores . Control coating thickness, make the cooling rate of all casting parts coincident. According to the thickness of the casting situation to select the appropriate mode. Refine microstructure and improve the ability of cracking. Improve the casting structure, eliminate mutation angle and wall thickness, reduce the hot cracking tendency.

Common defects of metal mold casting and the prevention methods